1. Field of the Invention
This invention relates to the field of dust removal technology, more specifically to a dust removal system for dust gas.
2. Description of the Related Arts
In the present metal processing industry, lots of dust gas is produced in the process of machining of metals. The dust in the dust gas comprises mostly different compounds.
For example, in the productive process of aluminum-titanium-boron alloy, the produced dust includes the following components: BF3, AlF3, Al2O3, KAlF4, K2TiF6, K8F4 and the dust mixes with air to form dust gas. The water mixture formed after the contact between this dust and NaOH solution has the following characteristics: first, high viscosity with high probability to adhere to metal surfaces; second, high probability to agglomerate with high speed of coagulation; third, corrosion to the metal in contact when the water mixture adheres to metal surfaces.
Presently, there are mainly three kinds of dust removal equipments:
The first kind is bag-type dust removal device, as shown in FIG. 1, wherein multiple bags 22 are set parallel along the radial direction of the collection chamber 20. The dust gas enters the device from the inlet of the collection chamber 20, passes through the micro-holes of the bags 22, and gets out from the outlet of the collection chamber 20. The micro-holes of the bags have a certain size, gas and dust with smaller sizes than the certain size can get through the bags, while dust with larger sizes than the certain size is filtered out and accumulates in the bags. This kind of bag-type dust removal device can filter dust gas, however, dust with high viscosity and high probability to agglomerate would easily block the micro-holes of the bags so that gas could not go through the device normally and the device is out of action. And the working life of this kind of device is very short; usually this device can work properly for only around 6 hours.
The second kind is fan-leaf-type dust removal device, as shown in FIG. 2, wherein a rotary fan body 23 is set in the atomizing chamber 21. There are two openings in the atomizing chamber 21; water flows in the atomizing chamber 21 from the upper opening and hits the rotary fan body 23 to form water mist; and the dust gas flows in the atomizing chamber 21 from the lower opening and mixes with the water mist to remove the dust in the dust gas. However, dust with corrosion effect would easily adhere to the surfaces of the fan body 23 and corrode the fan body, so that the atomization effect for water of the fan body is reduced.
The third kind is dense-spout-type dust removal device, as shown in FIG. 3, wherein a tubular water chamber 24 is set in the atomizing chamber 21, and dense small spouts 25 are set in the wall of the water chamber. Water flows in from the inlet of the water chamber 24 and sprays out from the dense small spouts 25 to form water mist, and the water mist mixes with the dust gas to remove the dust in the dust gas. However, when water sprays through the dense small spouts, vapor-water mixture surrounds the dense small spouts, so burrs have a high probability to accumulate on the surfaces of the spouts in contact with the vapor-water mixture, so that spouts are blocked slowly to reduce the atomization effect and at the same time are corroded to reduce the working life of this device. The necessity to clear burrs frequently in the process of using this device raises labor intensity and reduces the efficiency of removing dust.
So present dust removal equipments can not have stable, effective, and continually dust collection effect for the dust gas with compound dust.